Dynamics of cortical markers and Rho sensor during cellularization depend on Kinesin-1. (A) Images from movies with widefield optics during interphase 14/cellularization. Wild type or embryos depleted for slam or Kinesin-1 by maternal RNAi. Arrows in yellow point to the tip of the cellularization furrow. T = 0 when new nuclei appear during interphase 14/cellularization. (B) Ingression of the cellularization furrow. 20 furrows in four embryos for each genotype. Whiskers indicate SD. (C–G) Images from movies with fluorescence of indicated GFP markers during the onset of cellularization. T = 0 when new furrows appear between daughter nuclei. Arrows in yellow point to new furrows. Range of axial position as indicated. Maximal intensity projection. (C) GFP-Slam labels the tip of the furrow (basal domain). (D) Dia-GFP labels furrow tip (basal domain). (E) Rho sensor. (F) Canoe-YFP labels the emergent subapical domain in interphase 14. (G) Resille-GFP labels the plasma membrane. (H) Images of fixed embryos stained for Canoe (red), Slam (green), and DNA (blue) during interphase 12 and interphase 14. Genotype as indicated. Surface view and sagittal view. (I) Schematic drawing of cortical dynamics during mitosis 13 and interphase 14 in wild-type and Kinesin-1 RNAi. Scale bars 10 µm.